To mark Lung Cancer Awareness Month in November, we asked Dr. Jo-Anne Shepard, director of Thoracic Imaging and Intervention in the Mass General Department of Radiology, to explain the screening test and the impact of the recommendations.

What is a LDCT?

A low-dose CT (LDCT) scan for lung cancer uses advanced CT technology that delivers minimal radiation dose to detect small nodules at the early stage of lung cancer. It requires less than twenty seconds of scanning with no contrast injection or preparation.

Which patients are eligible for a LDCT at Mass General?

LDCTs to screen for lung cancer are available on a self-pay basis for high-risk patients who:

are 55 to 80 years old

have a 30 "pack year" or greater history of smoking (a "pack year" means that someone has smoked an average of one pack of cigarettes per day for a year)

are either current smokers or have quit in the past 15 years

have not had a chest CT for any reason within the past year

What are the benefits of a LDCT?

Research shows that low-dose CT screening can decrease the chance of lung cancer death in patients at high risk of the disease because it can find lung cancer in its early stages when treatment is most effective. According to one of the largest studies, low-dose CT screening can result in 20% fewer lung cancer deaths among high-risk patients compared to screening with a standard chest x-ray.

What are the risks of a LDCT?

Although we know that low-dose CT screening for lung cancer in patients at high risk can save lives, there is a negative aspect: the number of false-positive studies is high. It is very common to discover small nodules in the lung in as many as 30% of patients. Fortunately, 98% of these nodules are benign; however, follow-up LDCT scans are necessary to assess if they remain stable in size or grow. Questionable lung nodules require follow up to assess growth, which likely indicates cancer. Some large or growing nodules may also require biopsy to determine the presence of disease.

Additionally, as with all CT exams, a LDCT exposes a patient to radiation. The dose is about one-third or half of what a person receives annually from naturally occurring background radiation at sea level.

What does the Task Force recommendation mean for patients?

With widespread adoption, the recommendation has the potential to prevent 20,000 lung cancer deaths per year through early detection. About 90% of lung cancer patients die from the disease, frequently because it is not discovered until the later stages.

Will LDCTs now be covered by insurance?

LDCTs are currently not covered by most insurance plans. If an eligible patient pays for the test and requires further evaluation, follow-up LDCTs are typically covered by insurance.

After the Task Force finalizes its recommendations, private insurers and government health programs such as Medicare will likely cover the cost for high-risk patients who fit the Task Force's criteria.

How do patients access LDCTs?

Patients must have a physician referral for a LDCT. Physicians can order a LDCT at Mass General by using Physician Gateway or by calling 617-724-9729.